The present invention relates to a flow regulator device that may be utilized in varied applications.
In one application, the device of the present invention can be utilized in the process of cooling a bed of particulate material, such as cement clinker in a grate cooler, in which cooling gas from a source such as a fan is directed, via one or more ducts or channels, up through a gas distribution bottom that supports the bed of material to be treated and the bed of clinker material from one or more underlying compartments. In such a cooler the clinker is not always uniformly distributed on the cooler grate. Instead, the size and amount of the clinker to be cooled can be irregularly distributed on the cooler and the thickness of the clinker bed may exhibit variations both longitudinally and transversely through the cooler, which results in differing pressure drops through the clinker bed at different points throughout the cooler. Without a flow regulator, those areas in which there are lower pressure drop through the clinker bed—that is, those areas that have lightly packed, small amounts of clinker—will attract maximum amounts of cooling air and vice versa. Thus flow regulators are desirable to compensate for irregularities in clinker distribution throughout a clinker cooler.
In U.S. Pat. No. 6,082,021 there is described a means for self regulating the flow of the treatment gas through each duct of a gas distribution bottom by having a flow regulator provided in each duct to thereby reduce the total pressure loss across the gas distribution bottom and to distribute the flow of the treatment gas through the material bed. The flow regulator described in this patent senses changes in static pressure above, and adjusts its position to maintain a constant differential pressure across the grate assembly and clinker bed combination. By maintaining a constant differential pressure, the valve is able to ensure that the airflow through any one-grate assembly does not change. This regulated airflow optimizes cooler efficiency by preventing air from short-circuiting through sections of the clinker bed characterized by a lower resistance to gas flow. Another design of flow regulator is shown in Canadian patent 02550297 which comprises in part a vertically situated fluid permeable housing arranged below a cooling grate. The described flow regulator is claimed to achieve a constant airflow rate versus pressure drop.
It would be advantageous to have a flow regulator that has utility not only in applications which utilize a gas distribution bottom, such as a cement clinker cooler, fluidized bed reactor, chemical reactor, drying apparatus and gas-solid heat exchanger, but also in applications the flow regulator would not be positioned vertically, such as in wind boxes, burners or air ports in pulverized, solid fuel furnaces of power plants. The flow regulator of the present invention is particularly well suited to applications where the desired flow rate through the regulator needs to be adjustable during operation since only a single characteristic needs to be changed to achieve the desired flow rate; whereas most prior art flow regulators need to modify multiple characteristics simultaneously.